Sucralfate in the prevention of treatment-induced diarrhea in patients receiving pelvic radiation therapy: A North Central Cancer Treatment Group phase III double-blind placebo-controlled trial.
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PURPOSE: Randomized studies have suggested that sucralfate is effective in mitigating diarrhea during pelvic radiation therapy (RT). This North Central Cancer Treatment Group study was undertaken to confirm the antidiarrheal effect of sucralfate. Several other measures of bowel function were also assessed. PATIENTS AND METHODS: Patients receiving pelvic RT to a minimum of 45 Gy at 1.7 to 2.1 Gy/d were eligible for the study. Patients were assigned randomly, in double-blind fashion, to receive sucralfate (1.5 g orally every 6 hours) or an identical looking placebo during pelvic RT. RESULTS: One hundred twenty-three patients were randomly assigned and found assessable. Overall, there was no significant difference in patient characteristics between those receiving sucralfate and those receiving placebo. Moderate or worse diarrhea was observed in 53% of patients receiving sucralfate versus 41% of those receiving placebo. Compared with patients receiving placebo, more sucralfate-treated patients reported fecal incontinence (16% v 34%, respectively; P =. 04) and need for protective clothing (8% v 23%, respectively; P =. 04). The incidence and severity of nausea were worse among those taking sucralfate (P =.03). Analysis of patient-reported symptoms 10 to 12 months after RT showed a nonsignificant trend toward more problems in patients taking sucralfate than in those taking placebo (average, 2.3 v 1.9 problems, respectively; P =.34). CONCLUSION: Sucralfate did not decrease pelvic RT-related bowel toxicity by any of the end points measured and seems to have aggravated some gastrointestinal symptoms. (+info)
111In-labeled EGF is selectively radiotoxic to human breast cancer cells overexpressing EGFR.
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Our objective was to determine whether the internalization and nuclear translocation of human epidermal growth factor (hEGF) after binding to its cell surface receptor (EGFR) could be exploited to deliver the Auger electron emitter 111In into EGFR-positive breast cancer cells for targeted radiotherapy. METHODS: hEGF was derivatized with diethylenetriamine pentaacetic acid (DTPA) and radiolabeled with 111In-acetate. The internalization of 111In-DTPA-hEGF by MDA-MB-468 breast cancer cells (1.3x10(6) EGFRs/cell) was determined by displacement of surface-bound radioactivity by an acid wash. The radioactivity in the cell nucleus and chromatin, isolated by differential centrifugation, was measured. The effect on the growth rate of MDA-MB-468 or MCF-7 (1.5x10(4) EGFRs/cell) cells was determined after treatment in vitro with 111In-DTPA-hEGF, unlabeled DTPA-hEGF, or 111In-DTPA. The surviving fraction of MDA-MB-468 or MCF-7 cells treated in vitro with 111In-DTPA-hEGF was determined in a clonogenic assay. The radiotoxicity in vivo against normal hepatocytes or renal tubular cells was evaluated by measuring alanine aminotransferase (ALT) or creatinine levels in mice administered high amounts of 111In-DTPA-hEGF (equivalent to human doses up to 14,208 MBq) and by light and electron microscopy of the tissues. RESULTS: Approximately 70% of 111In-DTPA-hEGF was internalized by MDA-MB-468 cells within 15 min at 37 degrees C and up to 15% was translocated to the nucleus within 24 h. Chromatin contained 10% of internalized radioactivity. The growth rate of MDA-MB-468 cells was decreased 3-fold by treatment with 111In-DTPA-hEGF (45-60 mBq/cell). Treatment with unlabeled DTPA-hEGF caused a 1.5-fold decrease in growth rate, whereas treatment with 111In-DTPA had no effect. Targeting of MDA-MB-468 cells with up to 130 mBq/cell of 111In-DTPA-hEGF resulted in a 2-logarithm decrease in their surviving fraction. No decrease in the growth rate or surviving fraction of MCF-7 cells was evident. There was no evidence of hepatotoxicity or renal toxicity in mice administered high amounts of 111In-DTPA-hEGF. Radiation dosimetry estimates suggest that the radiation dose to an MDA-MB-468 cell targeted with 111In-DTPA-hEGF could be as high as 25 Gy with up to 19 Gy delivered to the cell nucleus. CONCLUSION: 111In-DTPA-hEGF is a promising novel radiopharmaceutical for targeted Auger electron radiotherapy of advanced, hormone-resistant breast cancer. (+info)
Fatigue, sexual function and mood following treatment for haematological malignancy: the impact of mild Leydig cell dysfunction.
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Fatigue, sexual dysfunction, anxiety and depression are all more common in patients who have previously been treated with cytotoxic chemotherapy and radiotherapy (XRT) for haematological malignancies. Following therapy, a significant proportion of men have biochemical evidence of Leydig cell dysfunction, defined by a raised luteinizing hormone level in the presence of a low/normal testosterone level. We postulated that mild testosterone deficiency may account for some of the long-term side-effects of treatment, and we have therefore assessed fatigue, mood and sexual function by questionnaire in 36 patients with Leydig cell dysfunction (group 1), and also in a group of 30 patients (group 2) with normal hormone levels who underwent the same treatment for cancer. There was no significant difference in anxiety and depression scores between the two groups although anxiety scores were higher than those previously reported for normal men. Eighty-seven per cent of group 2 were sexually active compared with only 69% of group 1 (P= 0.1), and patients in group 1 engaged less in sexual activity than those in group 2 (mean of 1.8 times per week compared with 3.2 times per week; P = 0.02) Fatigue scores were significantly higher in both groups compared with normal men, but there were no significant differences in any of the fatigue subscales between the two groups. We conclude that mild Leydig cell insufficiency following treatment with cytotoxic chemotherapy +/- XRT is not associated with higher levels of fatigue and anxiety but may result in reduced sexual function. These results do not provide a convincing argument that androgen replacement therapy is mandatory to improve quality of life in the majority of these patients, although it may be beneficial in a minority. To establish criteria for selection of patients for a trial of androgen therapy a randomized placebo-controlled study will be necessary. (+info)
Induction of cell death by radiotherapy.
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Ionising radiation remains one of the most effective tools in the therapy of cancer. It combines the properties of an extremely efficient DNA-damaging agent with a high degree of spatial specificity. Nonetheless, there remain considerable differences in the outcome for treatment of tumours of differing histological type treated by radiotherapy. Tumours arising from lymphoid or germ cells are significantly more radiocurable than most solid tumours of epithelial origin. The molecular mechanisms underlying such differences in cellular radiosensitivity are the subject of current research. When normal mammalian cells are subjected to stress signals--e.g. radiation, chemotherapeutic drugs, oxygen deficiency--a range of gene products involved in the sensing and signalling of such stresses are activated. The response of eukaryotic cells to ionising radiation includes activation of DNA repair pathways and cell cycle checkpoints, with subsequent full 'biological' recovery or cell death. Radiation induces two different modes of cell death termed mitotic or clonogenic cell death, and apoptosis. Until recent years, there was surprisingly little mechanistic understanding of the events following induction of physical damage by radiation and biological outcome for the cell. There have been recent major advances in our understanding of the signal transduction pathways involved in determining the fate of cells after irradiation. (+info)
Clinical studies of Bcl-2 and treatment benefit in breast cancer patients.
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Interest in translational studies aimed at investigating the role of biologic markers in predicting clinical outcome of breast cancer patients and, in particular, response to specific treatments, has progressively increased. Among biologic variables presently under investigation, apoptosis markers, in particular Bcl-2 and Bax expression, are receiving much attention for their relationship with the cellular response to genotoxic damage in experimental tumors. Retrospective, independent studies were carried out by several research groups on about 5000 patients with breast cancer at different stages and with an adequate follow-up. The outcome of separate analyses as a function of treatment generally demonstrated that Bcl-2 overexpression, which correlates with biologic features of a differentiated phenotype (slow proliferation, high steroid receptor levels, absence of p53 and c-erB-2 expression), is associated with a favorable outcome. Such a finding is mainly evident following surgery as well as endocrine treatment. Conversely, no or weak Bcl-2 expression, alone or in association with bax overexpression, appears indicative of a radiation response, and preliminary emerging evidence supports the involvement of such an association of apoptosis-related markers even as predictors of long-term response to neoadjuvant cytotoxic treatment. Although the findings of an involvement of Bcl-2 and Bax as determinants of treatment response should be confirmed within the context of randomized clinical trials, they indicate a combined consideration of proteins that negatively and positively regulate apoptosis in translational studies on the effect of chemical and physical agents at a cellular level. (+info)
Influence of postangioplasty beta-irradiation on endothelial function in porcine coronary arteries.
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BACKGROUND: Postangioplasty (PTCA) intracoronary radiation therapy (ICRT) has been demonstrated to limit restenosis. The consequences of these procedures on coronary reactivity are unknown. METHODS AND RESULTS: Porcine coronary arteries were studied after PTCA immediately (n=5) and 6 weeks (n=5) after ICRT (n=5 and 5, respectively), after combined PTCA+ICRT (n=5 and 7, respectively), and after no intervention (n=11). A 3-cm-long source train of Sr/Y(90) was used in vivo to deliver 16 Gy at a depth of 2 mm from the source center, as used in clinical trials. Arterial rings were mounted on myographs to record isometric tension. After achieving steady-state contraction to depolarizing physiological solution containing 40 mmol/L KCl, measured baseline tension was significantly elevated immediately after all interventions. It returned to normal levels 6 weeks after PTCA and ICRT alone but was significantly reduced if combined. Active contractions induced by 40 mmol/L KCl were maintained after combined therapy both immediately after and at 6 weeks. In these depolarizing conditions, nitric oxide-dependent relaxation to substance P was trivial after PTCA+ICRT and reduced after ICRT, whereas in the presence of physiological solution and N(omega)-nitro-L-arginine, substance P-induced relaxation was reduced after PTCA and abolished after PTCA+ICRT 6 weeks after intervention. In rings without endothelium, the relaxation mediated by sodium nitroprusside (0.1 micromol/L) was reduced immediately after PTCA and at 6 weeks. CONCLUSIONS: PTCA+ICRT altered the passive mechanical properties of porcine coronary arterial wall. Furthermore, at 6 weeks, receptor-operated release of endothelium-derived nitric oxide and endothelium-derived hyperpolarizing factor was reduced by ICRT and PTCA alone, respectively, and was prevented by their combination. (+info)
Possibilities of preventing osteoradionecrosis during complex therapy of tumors of the oral cavity.
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In recent years, there has been a dramatic increase in the number of tumors of the head and neck. Their successful treatment is one of the greatest challenges for physicians dealing with oncotherapy. An organic part of the complex therapy is preoperative or postoperative irradiation. Application of this is accompanied by a lower risk of recurrences, and by a higher proportion of cured patients. Unfortunately, irradiation also has a disadvantage: the development of osteoradionecrosis, a special form of osteomyelitis, in some patients (mainly in those cases where irradiation occurs after bone resection or after partial removal of the periosteum). Once the clinical picture of this irradiation complication has developed, its treatment is very difficult. A significant result or complete freedom from complaints can be attained only rarely. Attention must therefore be focussed primarily on prevention, and the oral surgeon, the oncoradiologist and the patient too can all do much to help prevent the occurrence of osteoradionecrosis. Through coupling of an up-to-date, functional surgical attitude with knowledge relating to modern radiology and radiation physics, the way may be opened to forestall this complication that is so difficult to cure. (+info)
Concomitant chemoradiotherapy as primary therapy for locoregionally advanced head and neck cancer.
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PURPOSE: To achieve locoregional control of head and neck cancer, survival, and organ preservation using intensive concomitant chemoradiotherapy. PATIENTS AND METHODS: This study was a phase II trial of chemoradiotherapy with cisplatin 100 mg/m(2) every 28 days, infusional fluorouracil 800 mg/m(2)/d for 5 days, hydroxyurea 1 g orally every 12 hours for 11 doses, and radiotherapy twice daily at 1.5 Gy/fraction on days 1 through 5 (total dose, 15 Gy). Five days of treatment were followed by 9 days of rest, during which time patients received granulocyte colony-stimulating factor. Five cycles (three with cisplatin) were administered over 10 weeks (total radiotherapy dose, locoregional). Surgery after concomitant chemoradiotherapy is feasible. Compliance with adjuvant chemoprevention is poor. Identification of less toxic regimens and improved distant disease control emerge as important future research goals. (+info)